You have taken the first step!

I quit 3 years ago next week and it was the best decision I ever made.

My recommendation is use the money you would have spent on cigarettes and either invest or treat yourself as motivation.

What about getting a money box for your son and putting the money away for him?

If ever feel like you need to have a smoke, pour a glass of water and keep drinking until you are full.

That's what helped me in the beginning :)